Ventilator to tracheotomy tube coupling

ABSTRACT

A coupling for connecting a ventilator tube to a tracheotomy tube has a latching mechanism which prevents the coupling from axially displacing a tapered tubular extension of the tracheotomy tube after they have been mated in a pneumatically discrete path. For use with known adult tracheotomy tubes which have inner and outer cannulas, the latching mechanism engages the coupling with the leading end of the outer cannula collar with the inner cannula collar sandwiched therebetween. For use with known one piece children&#39;s tracheotomy tubes, the latching mechanism is a clamshell contoured to concentrically grip the tapered tubular extension of the tracheotomy tube. Interlocking the coupling and the tracheotomy tube prevents them from inadvertently axially displacing from each other. Non-axial force disengages the coupling from the tracheotomy tube so that the coupling can be axially displaced without exertion of excessive axial force on the system and the patient.

BACKGROUND OF THE INVENTION

This invention relates generally to medical equipment and moreparticularly concerns devices used to connect ventilators to tracheotomytubes.

For adult patients, two-piece tracheotomy tubes having inner and outercannulas are presently in common use. The outer cannula is inserted intothe patient's windpipe and the inner cannula is inserted into or removedfrom the outer cannula for use or for replacement, cleaning ordisinfecting, respectively. The outer cannula of these two-piece deviceshas a collar on its trailing end which is configured to be positivelyengaged with a collar on the leading end of the inner cannula. Thecannulas cannot be disengaged from each other affirmative release oftheir positive engagement. The trailing end of the combined cannulas hasa tapered tubular extension which plugs into or into which is plugged,depending on the diameter of the tubular extension of the particulartracheotomy tube, the leading end of a flexible connector. The trailingend of the flexible connector is connected to a tube extending from theventilator or other external equipment. The present tapered tubularextension connection to the ventilator is dependent on mere insertion ofa tapered tube into a constant diameter tube in the hope of achieving asnug fit. To assist in making this connection, the flexible connectorshave annular flanges with significantly wider diameters than the tubularportions of the connectors so as to facilitate manipulation of theconnectors with the thumb and forefinger.

For children, a smaller, one piece tracheotomy tube is made from a verysoft, pliant material. The entire tracheotomy tube must be frequentlyremoved, at least once a week, from the child's trachea, cleaned anddisinfected and reinserted into the trachea. The same flanged flexibleconnector used with the adult devices is also used with the children'sdevices. The tapered tubular extension of the children's tracheotomytube is integral with the pliant tracheotomy tube and has a hard plasticouter sleeve which is inserted directly into the flexible connector. Anannular flange on the trailing end of the tubular extension of thechild's tracheotomy tube holds the hard plastic sleeve in place on theextension.

Because of their structural configuration and operational steps, thereare some problems inherent in the known one or two piece tracheotomytubes, in the known flexible connectors and in their combination.

One set of problems is related to the comfort of the patient. Theprofile of the flanged flexible connectors, falling generally betweenthe underside of the patient's chin and the patient's chest, fosters abreakdown of skin and tissue on the chin or chest, depending on the headmovements of the patient. This is especially true for children, theirchin-to-chest cavity being comparatively small. This concern issometimes addressed by after-market removal of all or a portion of theflange, but this solution generally results in a damaged connector,increasing the likelihood of infection-causing secretions and alsobecomes less secure due to removal of the firm portion of the connector.Also, the manipulation of the flange to connect or disconnect theconnector to or from the tubular extension can cause considerablediscomfort to the patient, since this often requires the application ofmanual pressure to the patient's neck, chin or chest. It is commonpractice to extend rubber bands from one side of a neck plate on thetracheotomy tube collar to the flexible connector and back to the otherside of the neck plate in an effort to hold the flexible connector inplace, but the rubber bands are likely either too elastic or tooinelastic to properly accomplish this purpose. While a child'stracheotomy tube is smaller than an adult's, the available space betweenthe chin and chest is significantly smaller and the flexible connectorflange is the same size as used for adults, so the smaller deviceaffords no relief for the connector flange related comfort problems.And, since the child's tracheotomy tubes are of one piece construction,the force necessary to disconnect the flexible connector may be directlyapplied to the patient's neck or windpipe.

A second set of problems is related directly to the ability, orinability, of the system to accomplish its primary purpose of keepingthe patient's trachea connected to the ventilator. To begin with,tapered connections tend to easily separate in the best ofcircumstances, there being minimal surface contact between the taperedand constant diameter components. Moreover, the connector andtracheotomy tube parts are always wet and slippery due to the verynature of their application and are not very tightly mated because ofthe neck pressure problems. The end result is a connection so tenuousthat a mere sneeze, cough or turn or tip of the head can cause theconnector and the tapered tubular extension to separate, defeating theoperation of the system. Even without a sneeze, cough, turn or tip, theflange itself functions as a lever against the chin or chest in responseto the patient's head movements, and the reciprocal levering by theflange will eventually cause the connector and the tubular extension todisconnect.

A third set of problems concerns the performance of the medical staff asa result of these other problems. The inherent comfort issues result inmore pains-taking, time-consuming effort by the staff in an effort toreduce the impact of these discomforts on the patient. And, because ofthe ease of inadvertent disconnection of the system, the staffunnecessarily spends valuable time monitoring and reconnecting theconnectors to the tubular extensions of the tracheotomy tubes.

It is, therefore, a primary object of this invention to provide animproved tracheotomy tube coupling. Another object of this invention isto provide a tracheotomy tube coupling which reduces a likelihood ofassociated patient discomfort. It is also an object of this invention toprovide a tracheotomy tube coupling which is more suitably profiled forpositioning between a patient's chin and chest. Still another object ofthis invention is to provide a tracheotomy tube coupling which isprofiled to reduce a likelihood of skin or tissue breakdown on apatient's chin and chest. A further object of this invention is toprovide a tracheotomy tube coupling which simplifies manipulation of thecoupling in relation to the patient. Yet another object of thisinvention to provide a tracheotomy tube coupling which reduces alikelihood of exertion of discomforting pressure on the chin, neck,chest or windpipe of a patient during connection or disconnection of thecoupling from the tracheotomy tube. An additional object of thisinvention is to provide a tracheotomy tube coupling which makesinadvertent disconnection of the tracheotomy tube from the connectedmedical equipment less likely. Another object of this invention is toprovide a tracheotomy tube coupling which does not rely on tapered toconstant diameter connections to maintain connection between thetracheotomy tube and its related equipment. It is also an object of thisinvention to provide a tracheotomy tube coupling which is profiled toreduce a likelihood that the coupling will operate as aself-disconnecting lever. Still another object of this invention toprovide a tracheotomy tube coupling which can be easily connected anddisconnected from the tracheotomy tube by the medical staff. A furtherobject of this invention is to provide a tracheotomy tube coupling whichcan reduce the time expended by the medical staff to monitor andmaintain the coupling connections. Yet another object of this inventionis to provide a tracheotomy tube coupling which facilitates more rapiddisassembly and reassembly of associated components from the tracheotomytube for cleaning and disinfecting purposes.

SUMMARY OF THE INVENTION

In accordance with the invention, a coupling is provided for connectinga ventilator tube to a tracheotomy tube. The ventilator tube has aconnector at its leading end and the tracheotomy tube has a taperedtubular extension on its trailing end. The coupling is a preferablyexpandable, flexible tubular member with a first adapter on its trailingend for connecting its trailing end in a pneumatic flow path to theventilator tube leading end connector and a second adapter on itsleading end for mating its leading end in a pneumatic flow path with thetrailing end of the tracheotomy tube. The second adapter has a latchingmechanism for engaging the leading end of the coupling to thetracheotomy tube to prevent the leading end of the tubular member fromaxially displacing from the trailing end of the tracheotomy tube afterthey have been mated in the pneumatic flow path. An unlatching mechanismis provided for disengaging the latching mechanism from the tracheotomytube so as to permit the leading end of the tubular member to axiallydisplace from the trailing end of the tracheotomy tube. The unlatchingmechanism is operated by non-axial forces so that the coupling can bedisengaged from the tracheotomy tube without exertion of excessive axialforce on the patient's neck.

Some known adult tracheotomy tubes have an inner cannula inserted into atrailing end of an outer cannula with the tubular extension on thetrailing end of the inner cannula. For such tracheotomy tubes, thecoupling tubular member has a first means on its leading end for matingthe tubular member in the pneumatic flow path with the tubular extensionof the inner cannula which is operable by motion of the mating means ina generally axial direction relative, to the tubular extension. A secondmeans is provided on the mating means for engaging with the outercannula during mating to prevent the leading end of the tubular memberfrom axially displacing from the tubular extension after mating. A thirdmeans is provided on the inner cannula for disengaging the engagingmeans from the outer cannula by application of force to the mating meansin other than the generally axial direction to permit the leading end ofthe tubular member to axially displace from the tubular extension of theinner cannula. Typically, the trailing end of the outer cannula hasopposed annular flanges and the engaging means consists of opposed meansfor resiliently snapping over the flanges. The disengaging meansconsists of means on the inner cannula for spreading the opposed flangesduring rotational motion of the mating means about a longitudinal axisof the tubular member.

Other known adult tracheotomy tubes have an inner cannula inserted intoa trailing end of an outer cannula with the tubular extension on thetrailing end of the inner cannula. For such tracheotomy tubes, thecoupling tubular member has a first means on a leading end of thetubular member for mating the tubular member in the pneumatic flow pathwith the tubular extension of the outer cannula by motion of the matingmeans in a generally axial direction relative to the tubular extension.A second means is provided on the mating means for engaging with theouter cannula during mating to prevent the tubular member from axiallydisplacing from the tubular extension after mating. A third means isprovided on the outer cannula which is operable by application of forceon the mating means in a direction other than the generally axialdirection for disengaging the engaging means from the outer cannula topermit the tubular member to axially displace from the tubular extensionof the outer cannula. Typically, the trailing end of the outer cannulahas annularly opposed flat notches. The disengaging means consists ofmeans on the outer cannula for spreading the opposed flanges duringrotational motion of the mating means about a longitudinal axis of thetubular member.

Known child tracheotomy tubes have a tubular extension on their trailingend. For such tracheotomy tubes, the coupling tubular member has a firstmeans for mating the leading end of the tubular member in the pneumaticflow path with the tubular extension of the tracheotomy tube by motionof the mating means in a generally axial direction relative to thetubular extension. A second means is provided on the mating means forengaging with the tracheotomy tube to prevent the leading end of thetubular member from axially displacing from the tubular extension aftermating. A third means is provided on the mating means which is operableby application of force on the mating means in other than the generallyaxial direction for disengaging the engaging means from the tracheotomytube to permit the tubular member to axially displace from the tubularextension of the tracheotomy tube. The mating means consists of a nozzleinsertable into the tubular extension. The engaging means consists of aclamshell, the clamshell and the tubular extension having complementarythree-dimensional surfaces which prevent axial displacement of theclamshell from the tubular extension gripped therein. Half of theclamshell has diametrically opposite lugs and another half of theclamshell has diametrically opposite fingers which resiliently snap overthe lugs when the clamshell is closed. The disengaging means consists ofmeans on the fingers for spreading the fingers in response to inwardradial pressure on the spreading means to release the lugs.

BRIEF DESCRIPTION OF THE DRAWINGS

Other objects and advantages of the invention will become apparent uponreading the following detailed description and upon reference to thedrawings in which:

FIG. 1 is a perspective view of a first type of known tracheotomy tubeouter cannula;

FIG. 2 is a perspective view of a first embodiment of an inner cannulafor use with the outer cannula of FIG. 1;

FIG. 3 is a perspective view of a first embodiment of a couplingconnected to the inner cannula of FIG. 2;

FIG. 4 is a side elevation assembly view of the coupling and cannulas ofFIGS. 1-3;

FIG. 5 is a top plan assembly view from the line 5-5 of FIG. 4;

FIG. 6 is a side elevation view of the assembled coupling and cannulasof FIGS. 1-3;

FIG. 7 is a perspective assembly view of the leading end adapter of thecoupling of FIG. 3 and the outer cannula of FIG. 1;

FIG. 8 is a side elevation view of the assembled leading end adapter ofthe coupling of FIG. 3 and inner cannula of FIG. 2;

FIG. 9 is a trailing end elevation view of the assembly of FIG. 8;

FIG. 10 is a top plan view of the assembly of FIG. 8;

FIG. 11 is a leading end elevation view of the assembly of FIG. 8;

FIG. 12 is a leading end perspective view of the leading end adapter ofthe coupling of FIG. 3;

FIG. 13 is a trailing end perspective view of the leading end adapter ofthe coupling of FIG. 3;

FIG. 14 is a side elevation view of the leading end adapter of thecoupling of FIG. 3;

FIG. 15 is a trailing end elevation view of the trailing end adapter ofthe coupling of FIG. 3;

FIG. 16 is a top plan view of the leading end adapter of the coupling ofFIG. 1;

FIG. 17 is a leading end perspective view of the inner cannula of FIG. 2and leading end adapter of the coupling of FIG. 3 in an operativelyassembled condition;

FIG. 18 is a leading end perspective view of the inner cannula of FIG. 2and leading end adapter of the coupling of FIG. 3 in aready-to-disconnect condition;

FIG. 19 is a perspective assembly view of a second embodiment of thecoupling and inner cannula in relationship to a second type of knowntracheotomy tube outer cannula;

FIG. 20 is a top plan assembly view of the coupling and cannulas of FIG.19;

FIG. 21 is a trailing end view of the leading end of the coupling ofFIG. 19;

FIG. 22 is a leading end view of the leading end of the coupling of FIG.19;

FIG. 23 is a side elevation view of the leading end of the coupling ofFIG. 19;

FIG. 24 is a top plan view of the leading end of the coupling of FIG.19;

FIG. 25 is a side elevation assembly view of the cannulas and couplingof FIG. 19;

FIG. 26 is a side elevation view of the assembled cannulas and couplingof FIG. 19;

FIG. 27 is a perspective assembly view of a third embodiment of thecoupling in relationship to a third type of known tracheotomy tube;

FIG. 28 is a top plan assembly view of the coupling and tracheotomy tubeof FIG. 27;

FIG. 29 is a leading end perspective view of the coupling of FIG. 27 inan open condition;

FIG. 30 is a leading end elevation view of the coupling of FIG. 27 inthe open condition;

FIG. 31 is a top plan view of the leading end of the coupling of FIG. 27in the open condition;

FIG. 32 is a side elevation view of the leading end of the coupling ofFIG. 27 in the open condition;

FIG. 33 is a side elevation assembly view of the coupling andtracheotomy tube of FIG. 27;

FIG. 34 is a side elevation view of the coupling and tracheotomy tube ofFIG. 27 with the leading end of the coupling in the open condition; and

FIG. 35 is a side elevation view of the assembled coupling andtracheotomy tube of FIG. 27.

While the invention will be described in connection with preferredembodiments thereof, it will be understood that it is not intended tolimit the invention to those embodiments or to the details of theconstruction or arrangement of parts illustrated in the accompanyingdrawings.

DETAILED DESCRIPTION

Tracheal Inserts: Adult tracheotomy tubes are illustrated in FIGS. 1-18,showing a tracheotomy tube with outer and inner cannulas 100 and 130 anda tapered tubular extension 139 on the trailing end of the inner cannula130 and FIGS. 19-26, showing a tracheotomy tube with outer and innercannulas 200 and 230 and a tapered tubular extension 223 on the trailingend of the outer cannula 200. A child's tracheotomy tube is illustratedin FIGS. 27-35. A child's tracheotomy tube has only one cannula which,for purposes of explanation of the invention is identified as an outercannula 300.

All three known outer cannulas 100, 200 and 300 are, in some respects,substantially similar, being arced tubes 101, 201 or 301 ofapproximately a quarter circle extending from a leading end 103, 203 or303 to a collar 105, 205 or 305 at the trailing end 107, 207 or 307 ofthe arced tube 101, 201 or 301. A cuff 109, 209 or 309 on the leadinghalf of the arced tube 101, 201 or 301 is inflatable via an air supplyline 111, 211 or 311. The arced tube 101, 201 or 301 is the trachealinsert portion of the tracheotomy tube and, once inserted, the cuff 109,209 or 309 is inflated to hold and seal the tube 101, 201 or 301 inposition in the trachea. Each of the outer cannulas 100, 200 or 300 hasa neck plate 115, 215 or 315 which positions the outer cannulas 100, 200or 300 against the patient's neck and is adapted to maximize itsmanipulability relative to the collar 105, 205 or 305 by connectinghinges 117 or by openings 217 or contours 317 in its body. Each of theneck plates 115, 215 or 315 also has openings 119, 219 or 319 forconnection of an adjustable strap to pass around and secure the neckplates 115, 215 or 315 against the patient's neck. The adult outercannulas 100 and 200 are comparatively hard and the child's outercannula 300 is very soft. From the collars 105, 205 and 305 on thetrailing ends of the arced tubes 101, 201 and 301 toward the trailingends of the outer cannulas 100, 200 and 300, the configurations of theouter cannulas 100, 200 and 300 are quite different.

Both inner cannulas 130 and 230 are also, in some respects,substantially similar, being arced tubes 131 or 231 of approximately aquarter circle extending from a leading end 133 or 233 to a collar 135or 235 on a trailing end 137 or 237 of the arced tube 131 or 231. Theinner cannulas 130 and 230 are inserted at their leading ends 131 and231 into the trailing ends of their outer cannulas 100 and 200 untiltheir trailing ends mate. From the collars 135 and 235 toward thetrailing ends of the inner cannulas 130 and 230, the inner cannulas 130and 230 are quite different.

The outer cannulas 100, 200 and 300 and their associated known innercannulas have mechanisms which positively engage them against separationin their mated condition. They all present tapered tubular extensionsfor connection with known flexible connectors. The connection to knownflexible connectors is universally accomplished by mere insertion of atapered end of a tube into a constant diameter tube. The followingillustrated embodiments of the outer cannulas 100, 200 and 300 aresubstantially the same as the known outer cannulas. The illustratedembodiments of the inner cannulas 130 and 230 and the flexibleconnectors or couplings 160, 260 and 360 are substantially differentfrom the known inner cannulas and connectors so as to permit a positiveengagement of the outer cannulas with their flexible connectors.However, they have been configured to work with the known outer cannulas100, 200 and 300. The principles of the invention, however, are fullyapplicable to the connection of flexible connectors to outer cannulasother than those herein illustrated.

First Adult Tracheotomy Tube Embodiment: Looking now at FIGS. 1-18, thefirst, type of adult tracheotomy tube is illustrated. As best seen inFIG. 1, the collar 105 on the outer cannula 100 has an annular ring 121which is concentric about the trailing end 107 of the outer cannula tube101 and has top and bottom quarter arcs 123 which extend concentricallyon and in a trailing direction from the ring 121. A concentric groove125 is also provided in the face of the trailing end 107 of the outercannula tube 101.

Looking at FIGS. 1-3 and 8-11, the inner cannula 130 applies theprinciples of the invention to the outer cannula 100. A soft arced tube131 extends upwardly and rearwardly from its leading end 133 to a hardcollar 135 on its trailing end 137. The collar 135 tapers outwardly to awider, concentric, hard, tapered tubular extension 139 which extends ina trailing direction from the collar 135. The extension 139 taperstoward its trailing end face 141. The collar 135 has a pair ofdiametrically opposed latches 143, as shown appearing at approximatelythe 2 and 8 o'clock orientations when looking at the trailing end face141 of the inner cannula 130. The latches 143 have fingers 145 whichextend radially inwardly therefrom for engagement against the trailingface of the annular ring 121 on the trailing end 103 of the outercannula 100. The fingers 145 extend in the leading end direction fromresiliently flexible supports 147 on the collar 135. Squeeze plates 149extend in the trailing end direction from the fingers 145. The leadingfaces 151 of the fingers 145 are beveled so that, as the inner cannula130 is inserted into the outer cannula 100 and the beveled faces contactthe annular ring 121, the supports 147 flex to widen the distancebetween the fingers 145. Once the fingers 145 pass over the annular ring121, the supports return to their unbiased condition in which thetrailing faces of the fingers 145 engage the leading face of the ring121, thus locking the inner cannula 130 in place on the outer cannula100. The squeeze plates 149 provide suitable surfaces and leverage forthe thumb and forefinger to apply pressure to flex the support 147 andspread the fingers 145 so that the fingers 145 can be disengaged fromthe annular ring 121. The squeeze plates 149 have alignment indicia suchas arrows 153, as shown diametrically opposed and pointing in thetrailing end direction. As best seen in FIGS. 6, 8, 9, 11, 17 and 18,the collar 135 also has diametrically opposed rotational andlongitudinal ramps 155 and 157 and longitudinal beads 159 for reasonshereinafter explained.

Looking at FIGS. 1-16, the flexible connector 160 for use with the aboveouter and inner cannulas 100 and 130 has a leading end adapter 161, bestseen in FIGS. 5, 7 and 12-15. The leading end adapter 161 has a hardouter sleeve 167 with a soft tube liner 169. The trailing end 171 of thesleeve 167 is of narrower diameter so as to provide a connecting ring173 for reasons hereinafter explained. The outer sleeve 167 hasdiametrically opposed posts 175 on its wide circumference at the leadingend of the connecting ring 173. A pair of diametrically opposedresiliently flexible arms 177 extend longitudinally from the sleeve 167to radially inwardly extending fingers 179. The sleeve 167 also hasalignment indicia such as arrows 181 pointing in the leading enddirection. The flexible connector 160 is in proper rotationalorientation for connection to the outer and inner cannulas 100 and 130when the arrows 153 on the inner cannula 130 are aligned with the arrows181 on the connector sleeve 167. As best seen in FIG. 6, when the arrows153 and 181 are aligned, the connector arms 177 can pass under thesqueeze plates 149 of the inner cannula latches 143 with the flexibleconnector fingers 179 at approximately the 4 and 10 o'clockorientations. This positions the connector fingers 179 on the clockwiseside of the rotational and longitudinal ramps 155 and 157 when theconnector 160 is connected to the outer and inner cannulas 100 and 130.The leading faces 183 of the connector fingers 179 are beveled so that,as the flexible connector 160 is moved longitudinally into the taperedtubular extension 139 of the inner cannula 130, the fingers 179 will bespread apart by and slide across the ring 121, on the outer cannula 100.Once the fingers 179 pass the ring 121 they resiliently close to securethe flexible connector 160 to the outer cannula 100. The inner cannulacollar 135 is sandwiched between them.

As best seen in FIG. 12, the interior surfaces of the connector arms 177are provided with longitudinal grooves 185 and the counterclockwiseinside edges of the connector arms 177 are provided with longitudinalbevels 187. To remove the flexible connector 160 from the outer andinner cannulas 100 and 130, the connector 160 is rotatedcounterclockwise, as indicated by the rotational arrows 189, using thethumb and forefinger on the posts 175. As the connector 160 rotates, thelongitudinal bevels 187 on the connector arms 177 ride on the rotationalramps 155 on the inner cannula collar 135 to unlatch the connectorfingers 179 from the collar 135. The rotation is limited to the point ofabutment of the inner cannula and connector fingers 145 and 179,whereupon longitudinal beads 159 on the inner cannula collar 135 andgrooves 185 on the connector arms 177 engage to provide an audible clickindicating that the connector 160 can be longitudinally displaced anddisconnected from the outer and inner cannulas 100 and 130. As theconnector 160 is withdrawn in the trailing direction, the connectorfingers 179 ride on the longitudinal ramp 157 of the inner cannulacollar 135 to assure that the connector fingers 179 cannot relatchduring the process.

Second Adult Tracheotomy Tube Embodiment: Turning to FIGS. 19-26, theother type of adult tracheotomy tube is illustrated. The collar 205 ofthe outer cannula 200 has a hard annular ring 221 which is concentricabout the trailing end 207 of the outer cannula tube 201. The hardtapered tubular extension 223 of the ring 221 narrows toward thetrailing end 225. Top and bottom approximately quarter notches 227 areprovided in the outer circumference of the tapered tubular extension 223at the trailing end of the ring 221.

The inner cannula 230 applies the principles of the invention to theouter cannula 200. A soft arced tube 231 extends upwardly and rearwardlyfrom its leading end 223 to a concentric collar 235 on its trailing end237. A tapered tubular extension 239 extends in a trailing directionfrom the collar 235 to a trailing end face 241 of an annular ring 243 onthe extension 239. The outside wall of the extension 239 has annularridges 245 which complement the annular grooves 229 in the inside wallof the outer cannula tapered extension 223 to secure the inner cannula230 in place in the outer cannula 200. A pair of vertically alignedstuds 247 are provided on the trailing end face 241 of the inner cannulaextension 239 for reasons hereinafter explained. A concentric pull ring249 is hinged 251 to the bottom of the end face 241 of the extensions239 to facilitate removal of the inner cannula 230 from the outercannula 200. An annular outer flange 253 on the midportion of the innercannula arced tube 231 helps to hold the inner cannula tube 231concentrically within the outer cannula tube 201.

The flexible connector 260 for use with the above outer and innercannulas 200 and 230 has a leading end adapter 261, best seen in FIGS.21-24. The leading end adapter 261 has a hard outer sleeve 267 with asoft tube liner 269. The trailing end 271 of the sleeve 267 is ofnarrower diameter so as to provide a connecting ring 273 for reasonshereinafter explained. The outer sleeve 267 has a corrugated surface 275to facilitate manipulation of the flexible connector 260. Diametricallyvertically opposed arms 277 with radially inwardly extending fingers 279at their leading ends are defined by longitudinal slots 281 in thesleeve 267. The fingers 279 are contoured to engage in the opposednotches 227 in the outer cannula tapered tubular extension 223. As bestseen in FIG. 23, valleys 283 in the inner and outer surfaces of the arms277 at their trailing ends permit the arms 277 to flex easily. As bestseen in FIGS. 21 and 22, the leading face of the connecting ring 273 ofthe leading end adapter 261 has notches 285 which receive the studs 247on the trailing end face 241 of the inner cannula 230. The notches 285extend clockwise from the point of longitudinal insertion of the studs247 to stops 287. Counterclockwise rotation of the leading end adapter261 of the connector 260, indicated by the rotational arrows 289 on thesleeve 267, is terminated by the studs 247 striking the stops 287. Atthis point, the connector arms 277 will have flexed sufficiently todisengage the connector fingers 279 from the notches 227 in the outercannula extension 223 so that the connector 260 can be longitudinallywithdrawn from the outer and inner cannulas 200 and 230.

Child Tracheotomy Tube Embodiment: Turning to FIGS. 27-35, the child'stracheotomy tube is illustrated. As best seen in FIG. 27, the collar 305on the soft tube 301 has a concentric annular ring 321 extending in atrailing direction with a soft tapered extension 323 extending in atrailing direction from the ring 321. The extension 323 has annularridges 325 in its circumference and a beveled flange 327 with an annulargroove 329 in its trailing end face. A hard sleeve 331 is tapered toconcentrically cover the tapered extension 323. The hard sleeve 331 hasa pair of annular flanges 333 at its leading end defining an annulargroove 335 therebetween. When the sleeve 331 is mounted on the softtapered extension 323, the leading face 337 of the sleeve 331 abuts thetrailing end face of the ring 321 on the collar 305 and the trailing endface 341 of the sleeve 331 abuts the leading end face of the beveledflange 327 on the tapered extension 323, locking the hard sleeve 331 inplace on the soft extension 323.

Looking at FIGS. 27-35, the flexible connector 360 for use with thecannula 300 has a leading end adapter 361, best seen in FIGS. 29-32. Theleading end adapter 361 is a clamshell-type grip with bottom and topshells 367 and 369. The shells 367 and 369 extend from a trailing endface 371 on a trailing connecting ring 373 to a leading connecting ring375 separated by a narrower body 377. As best seen in FIG. 35, theshells 367 and 369 are defined by a radial cut 379 splitting the tophalf of the trailing connecting ring 373 and a horizontal diametric cut381 extending from the radial cut 379 through the leading connectingring 375. The shells 367 and 369 are hinged 383 at the top of the radialcut 379. The leading connecting ring 375 has grooves 385 defining aridge 387 which will engage in the groove 335 on the leading end of thehard sleeve 331 mounted on the soft tapered tubular extension 323 of thecannula 300. A tapered nozzle 397 extends in a leading direction fromthe leading face of the trailing connecting ring 373. The nozzle 397 hasan annular bead 399 on the perimeter of its leading face. A concentricbead 401 is provided on the leading face of the trailing connecting ring373 around the nozzle 397. The annular bead 399 on the nozzle 397 abutsthe inside wall of the soft tapered tubular extension 323 of the cannula300 and the concentric bead 401 on the leading connecting ring 375 seatsin the groove 329 on the leading face on the beaded flange 327 of thesoft tapered tubular extension 323 of the cannula 300 when the softextension 323 with the hard sleeve 331 are longitudinally inserted intothe clamshell of the connector 360. As best seen in FIGS. 29-32,flexibly resilient supports 403 extend radially outwardly from the topshell portion of the body 377 at the diametric cut 381. Arms 405 extenddownwardly, considering the clamshell in the closed condition of FIG.35, from each of the supports 403 to fingers 407 which extenddiametrically inwardly from the arms 405. The fingers 40 have beads 409on their upper inside edges. The arms 405 also extend upwardly from thesupports 403 to corrugated squeeze plates 411 which aid in manuallyflexing the arms 405 between the thumb and forefinger. To cooperate withthe fingers 407, L-shaped lugs 413 extend upwardly, again consideringthe clamshell in the closed condition of FIG. 35, from the bottom shellportion of the body 377 at the diametric cut 381. When the top shell 369is closed on the bottom shell 367, the fingers 407 snap under the lugs413 and the beads 409 engage the inside edges of the lugs 413 to assurea stable engagement.

Common Connector Components: Each of the flexible connectors 160, 260and 360 has its own unique leading end adapter 161, 261 and 361 as abovedescribed. The trailing end adapters 163, 263 and 363 and intermediatetubes 165, 265 and 365 are substantially the same. Each of theintermediate tubes 165, 265 and 365 has a hard annular seat 191, 291 and391 at its leading end. The connecting ring 173, 273 and 373 at thetrailing end of each leading end adapter 161, 261 and 361 fits in and isfixed to the seat 191, 291 and 391 of the leading end of theintermediate tube 165, 265 and 365, as by ultrasonic welding. Thetrailing end adapters 163, 263 and 363 have hard tubular extensions 193,293 and 393 with annular flanges 195, 295 and 395 to facilitatemanipulation of the connectors 160, 260 and 360 during attachment to theventilator. The trailing end adapters 161, 261 and 361 are fixed to thetrailing ends of their intermediate tubes 165, 265 and 365, also as byultrasonic welding.

Common Operational Features of the Embodiments: For each of thedifferent tracheotomy tube outer cannulas 100, 200 and 300, thecorresponding coupling 160, 260 and 360 has a leading end adapter 161,261 and 361 which interlocks with its respective tracheotomy tube outercannulas 100, 200 and 300 preventing them from inadvertently axiallydisplacing from each other. However, non-axial force applied to theunlatching mechanisms disengage the associated adapters 161, 261 and 361from its tracheotomy tube outer cannula 100, 200 and 300 so that thecoupling 160, 260 and 360 can be axially displaced without exertion ofexcessive axial force on the system and the patient.

Thus, it is apparent that there has been provided, in accordance withthe invention, a ventilator to tracheotomy tube coupling that fullysatisfies the objects, aims and advantages set forth above. While theinvention has been described in conjunction with specific embodimentsthereof, it is evident that many alternatives, modifications andvariations will be apparent to those skilled in the art and in light ofthe foregoing description. Accordingly, it is intended to embrace allsuch alternatives, modifications and variations as fall within thespirit of the appended claims.

1. For connecting a ventilator tube having a connector at a leading endthereof to a tubular extension at a trailing end of a tracheotomy tube,a coupling comprising: a tubular member; means on a trailing end of saidtubular member for connecting said trailing end of said tubular memberin a pneumatic flow path to the ventilator tube leading end connector;means on a leading end of said tubular member for mating said leadingend of said tubular member in said pneumatic flow path with the tubularextension of the tracheotomy tube by motion of said mating means in agenerally axial direction relative to the tubular extension; and meanson said means for mating for engaging with the tracheotomy tube duringmating to prevent said leading end of said tubular member from axiallydisplacing from the tubular extension after mating.
 2. A couplingaccording to claim 1 further comprising means on said means for engagingoperable by application of force in a direction other than saidgenerally axial direction for disengaging said engaging means from thetracheotomy tube.
 3. For connecting a ventilator tube having a connectorat a leading end thereof to a tracheotomy tube having an outer cannulaand an inner cannula, the inner cannula being inserted into a trailingend of the outer cannula and having a tubular extension on a trailingthereof, a coupling comprising: a tubular member; means on a trailingend of said tubular member for connecting said trailing end of saidtubular member in a pneumatic flow path to the ventilator tube leadingend connector; means on a leading end of said tubular member for matingsaid leading end of said tubular member in said pneumatic flow path withthe tubular extension of the inner cannula by motion of said matingmeans in a generally axial direction relative to the tubular extension;and means on said means for mating for engaging with the outer cannuladuring mating to prevent said leading end of said tubular member fromaxially displacing from the tubular extension after mating.
 4. Acoupling according to claim 3 further comprising means on the innercannula for disengaging said engaging means from the outer cannula byapplication of force to said mating means in other than said generallyaxial direction to permit said leading end of said tubular member toaxially displace from the tubular extension of the inner cannula.
 5. Acoupling according to claim 4, the trailing end of the outer cannulahaving opposed annular flanges and said means for engaging comprisingopposed means for resiliently snapping over said flanges.
 6. A couplingaccording to claim 5, said means for disengaging comprising means on theinner cannula for spreading said opposed flanges during rotationalmotion of said mating means about a longitudinal axis of said tubularmember.
 7. For connecting a ventilator tube having a connector at aleading end thereof to a tracheotomy tube having an outer cannula and aninner cannula, the inner cannula being inserted into a trailing end ofthe outer cannula and the outer cannula having a tubular extension on atrailing thereof, a coupling comprising: a tubular member; means on atrailing end of said tubular member for connecting said trailing end ofsaid tubular member in a pneumatic flow path to the ventilator tubeleading end connector; means on a leading end of said tubular member formating said leading end of said tubular member in said pneumatic flowpath with the tubular extension of the outer cannula by motion of saidmating means in a generally axial direction relative to the tubularextension; and means on said means for mating for engaging with theouter cannula during mating to prevent said leading end of said tubularmember from axially displacing from the tubular extension after mating.8. A coupling according to claim 7 further comprising means on the outercannula operable by application of force on said mating means in adirection other than said generally axial direction for disengaging saidengaging means from the outer cannula to permit said leading end of saidtubular member to axially displace from the tubular extension of theouter cannula.
 9. A coupling according to claim 8, the trailing end ofthe outer cannula having annularly opposed flat notches and said meansfor engaging comprising opposed means for resiliently snapping into saidnotches.
 10. A coupling according to claim 9, said means for disengagingcomprising means on the outer cannula for spreading said opposed flangesduring rotational motion of said mating means about a longitudinal axisof said tubular member.
 11. For connecting a ventilator tube having aconnector at a leading end thereof to a tracheotomy tube having atubular extension on a trailing thereof, a coupling comprising: atubular member; means on a trailing end of said tubular member forconnecting said trailing end of said tubular member in a pneumatic flowpath to the ventilator tube leading end connector; means on a leadingend of said tubular member for mating said leading end of said tubularmember in said pneumatic flow path with the tubular extension of thetracheotomy tube by motion of said mating means in a generally axialdirection relative to the tubular extension; and means on said means formating for engaging with the tracheotomy tube to prevent said leadingend of said tubular member from axially displacing from the tubularextension after mating.
 12. A coupling according to claim 11 furthercomprising means on said mating means operable by application of forceon said mating means in other than said generally axial direction fordisengaging said engaging means from the tracheotomy tube to permit saidleading end of said tubular member to axially displace from the tubularextension of the tracheotomy tube.
 13. A coupling according to claim 12,said mating means comprising a nozzle insertable into the tubularextension.
 14. A coupling according to claim 13, said engaging meanscomprising a clamshell, said clamshell and said tubular extension havecomplementary three-dimensional surfaces preventing axial displacementof said clamshell from said tubular extension gripped therein.
 15. Acoupling according to claim 14, a half of said clamshell havingdiametrically opposite lugs and another half of said clamshell havingdiametrically opposite fingers for resiliently snapping over said lugswhen said clamshell is closed.
 16. A coupling according to claim 15,said means for disengaging comprising means on said fingers forspreading said fingers to release said lugs in response to inward radialpressure on said spreading means.